/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.solr.search.function;

import org.apache.lucene.index.IndexReader;
import org.apache.lucene.search.FieldCache;

import java.io.IOException;
import java.util.Map;

/**
 * Obtains float field values from the
 * {@link org.apache.lucene.search.FieldCache} using <code>getFloats()</code>
 * and makes those values available as other numeric types, casting as needed.
 * 
 * @version $Id:$
 */

public class DoubleFieldSource extends FieldCacheSource {
	protected FieldCache.DoubleParser parser;

	public DoubleFieldSource(String field) {
		this(field, null);
	}

	public DoubleFieldSource(String field, FieldCache.DoubleParser parser) {
		super(field);
		this.parser = parser;
	}

	@Override
	public String description() {
		return "double(" + field + ')';
	}

	@Override
	public DocValues getValues(Map context, IndexReader reader)
			throws IOException {
		final double[] arr = (parser == null) ? cache.getDoubles(reader, field)
				: cache.getDoubles(reader, field, parser);
		return new DocValues() {
			@Override
			public float floatVal(int doc) {
				return (float) arr[doc];
			}

			@Override
			public int intVal(int doc) {
				return (int) arr[doc];
			}

			@Override
			public long longVal(int doc) {
				return (long) arr[doc];
			}

			@Override
			public double doubleVal(int doc) {
				return arr[doc];
			}

			@Override
			public String strVal(int doc) {
				return Double.toString(arr[doc]);
			}

			@Override
			public String toString(int doc) {
				return description() + '=' + doubleVal(doc);
			}

			@Override
			public ValueSourceScorer getRangeScorer(IndexReader reader,
					String lowerVal, String upperVal, boolean includeLower,
					boolean includeUpper) {
				double lower, upper;

				if (lowerVal == null) {
					lower = Double.NEGATIVE_INFINITY;
				} else {
					lower = Double.parseDouble(lowerVal);
				}

				if (upperVal == null) {
					upper = Double.POSITIVE_INFINITY;
				} else {
					upper = Double.parseDouble(upperVal);
				}

				final double l = lower;
				final double u = upper;

				if (includeLower && includeUpper) {
					return new ValueSourceScorer(reader, this) {
						@Override
						public boolean matchesValue(int doc) {
							double docVal = doubleVal(doc);
							return docVal >= l && docVal <= u;
						}
					};
				} else if (includeLower && !includeUpper) {
					return new ValueSourceScorer(reader, this) {
						@Override
						public boolean matchesValue(int doc) {
							double docVal = doubleVal(doc);
							return docVal >= l && docVal < u;
						}
					};
				} else if (!includeLower && includeUpper) {
					return new ValueSourceScorer(reader, this) {
						@Override
						public boolean matchesValue(int doc) {
							double docVal = doubleVal(doc);
							return docVal > l && docVal <= u;
						}
					};
				} else {
					return new ValueSourceScorer(reader, this) {
						@Override
						public boolean matchesValue(int doc) {
							double docVal = doubleVal(doc);
							return docVal > l && docVal < u;
						}
					};
				}
			}

		};

	}

	@Override
	public boolean equals(Object o) {
		if (o.getClass() != DoubleFieldSource.class)
			return false;
		DoubleFieldSource other = (DoubleFieldSource) o;
		return super.equals(other)
				&& (this.parser == null ? other.parser == null : this.parser
						.getClass() == other.parser.getClass());
	}

	@Override
	public int hashCode() {
		int h = parser == null ? Double.class.hashCode() : parser.getClass()
				.hashCode();
		h += super.hashCode();
		return h;
	}

}
